"""支付服务模块"""
from typing import Optional, Dict, Any
from datetime import datetime
from decimal import Decimal
import uuid

from src.models.wallet import Wallet
from src.models.transaction import Transaction, TransactionType, TransactionStatus
from src.models.user import User
from sqlalchemy.orm import Session


class PaymentService:
    """支付服务类"""
    
    @staticmethod
    def create_payment_order(
        db: Session,
        user_id: int,
        amount: Decimal,
        payment_method: str,
        order_id: str = None,
        description: str = None
    ) -> Dict[str, Any]:
        """创建支付订单
        
        Args:
            db: 数据库会话
            user_id: 用户ID
            amount: 支付金额
            payment_method: 支付方式
            order_id: 订单ID，如果不提供则自动生成
            description: 订单描述
        
        Returns:
            支付订单信息
        """
        if not order_id:
            order_id = f"ORD-{datetime.now().strftime('%Y%m%d%H%M%S')}-{uuid.uuid4().hex[:8]}"
        
        # 构建支付订单信息
        payment_order = {
            "order_id": order_id,
            "user_id": user_id,
            "amount": amount,
            "payment_method": payment_method,
            "status": "pending",
            "created_at": datetime.now(),
            "description": description or f"支付订单 {order_id}"
        }
        
        # 这里可以根据不同的支付方式创建相应的支付请求
        # 例如：微信支付、支付宝、银行转账等
        
        return payment_order
    
    @staticmethod
    def process_wallet_payment(
        db: Session,
        user_id: int,
        amount: Decimal,
        order_id: str,
        description: str = None
    ) -> Dict[str, Any]:
        """处理钱包支付
        
        Args:
            db: 数据库会话
            user_id: 用户ID
            amount: 支付金额
            order_id: 订单ID
            description: 订单描述
        
        Returns:
            支付结果
        
        Raises:
            ValueError: 当钱包余额不足或支付失败时
        """
        # 获取用户钱包
        wallet = db.query(Wallet).filter(Wallet.user_id == user_id).first()
        if not wallet:
            raise ValueError("钱包不存在")
        
        # 检查余额
        if wallet.balance < amount:
            raise ValueError("钱包余额不足")
        
        try:
            # 扣除余额
            wallet.balance -= amount
            
            # 创建交易记录
            transaction = Transaction(
                wallet_id=wallet.id,
                amount=float(amount),
                type=TransactionType.PAYMENT,
                status=TransactionStatus.COMPLETED,
                description=description or f"支付订单 {order_id}"
            )
            
            db.add(transaction)
            db.commit()
            
            return {
                "status": "success",
                "transaction_id": transaction.id,
                "order_id": order_id,
                "amount": amount,
                "remaining_balance": wallet.balance
            }
        except Exception as e:
            db.rollback()
            raise ValueError(f"支付处理失败: {str(e)}")
    
    @staticmethod
    def process_wallet_recharge(
        db: Session,
        user_id: int,
        amount: Decimal,
        payment_method: str,
        order_id: str,
        description: str = None
    ) -> Dict[str, Any]:
        """处理钱包充值
        
        Args:
            db: 数据库会话
            user_id: 用户ID
            amount: 充值金额
            payment_method: 支付方式
            order_id: 订单ID
            description: 充值描述
        
        Returns:
            充值结果
        
        Raises:
            ValueError: 当充值处理失败时
        """
        # 获取或创建用户钱包
        wallet = db.query(Wallet).filter(Wallet.user_id == user_id).first()
        if not wallet:
            wallet = Wallet(user_id=user_id, balance=Decimal('0.0'))
            db.add(wallet)
        
        try:
            # 增加余额
            wallet.balance += amount
            
            # 创建交易记录
            transaction = Transaction(
                wallet_id=wallet.id,
                amount=float(amount),
                type=TransactionType.DEPOSIT,
                status=TransactionStatus.COMPLETED,
                description=description or f"通过{payment_method}充值 {amount}元"
            )
            
            db.add(transaction)
            db.commit()
            db.refresh(wallet)
            
            return {
                "status": "success",
                "transaction_id": transaction.id,
                "order_id": order_id,
                "amount": amount,
                "new_balance": wallet.balance
            }
        except Exception as e:
            db.rollback()
            raise ValueError(f"充值处理失败: {str(e)}")
    
    @staticmethod
    def process_payment_callback(
        db: Session,
        payment_method: str,
        callback_data: Dict[str, Any]
    ) -> Dict[str, Any]:
        """处理支付回调
        
        Args:
            db: 数据库会话
            payment_method: 支付方式
            callback_data: 回调数据
        
        Returns:
            回调处理结果
        """
        # 这里根据不同的支付方式处理回调数据
        # 验证签名、更新订单状态等
        
        # 示例：简化的回调处理逻辑
        order_id = callback_data.get("order_id")
        payment_status = callback_data.get("status")
        transaction_id = callback_data.get("transaction_id")
        amount = Decimal(str(callback_data.get("amount", 0)))
        
        if payment_status == "success":
            # 更新相关的订单状态、交易记录等
            # 这里需要根据具体业务逻辑实现
            return {
                "status": "success",
                "message": "支付回调处理成功",
                "order_id": order_id,
                "transaction_id": transaction_id
            }
        else:
            return {
                "status": "failed",
                "message": "支付失败",
                "order_id": order_id
            }
    
    @staticmethod
    def refund_payment(
        db: Session,
        user_id: int,
        amount: Decimal,
        order_id: str,
        refund_reason: str = None
    ) -> Dict[str, Any]:
        """处理退款
        
        Args:
            db: 数据库会话
            user_id: 用户ID
            amount: 退款金额
            order_id: 订单ID
            refund_reason: 退款原因
        
        Returns:
            退款结果
        
        Raises:
            ValueError: 当退款处理失败时
        """
        # 获取用户钱包
        wallet = db.query(Wallet).filter(Wallet.user_id == user_id).first()
        if not wallet:
            wallet = Wallet(user_id=user_id, balance=Decimal('0.0'))
            db.add(wallet)
        
        try:
            # 增加余额（退款）
            wallet.balance += amount
            
            # 创建交易记录
            transaction = Transaction(
                wallet_id=wallet.id,
                amount=float(amount),
                type=TransactionType.REFUND,
                status=TransactionStatus.COMPLETED,
                description=f"订单 {order_id} 退款，原因：{refund_reason or '无'}"
            )
            
            db.add(transaction)
            db.commit()
            db.refresh(wallet)
            
            return {
                "status": "success",
                "transaction_id": transaction.id,
                "order_id": order_id,
                "refund_amount": amount,
                "new_balance": wallet.balance
            }
        except Exception as e:
            db.rollback()
            raise ValueError(f"退款处理失败: {str(e)}")
    
    @staticmethod
    def validate_payment(
        db: Session,
        order_id: str,
        user_id: int
    ) -> Optional[Dict[str, Any]]:
        """验证支付状态
        
        Args:
            db: 数据库会话
            order_id: 订单ID
            user_id: 用户ID
        
        Returns:
            支付状态信息，如果找不到则返回None
        """
        # 查找相关的支付记录
        # 这里需要根据具体的业务逻辑实现
        # 例如：查询交易表、支付记录表等
        
        # 示例：简化的验证逻辑
        wallet = db.query(Wallet).filter(Wallet.user_id == user_id).first()
        if wallet:
            # 查找包含该订单ID的交易记录
            transaction = db.query(Transaction).join(Wallet).filter(
                Wallet.user_id == user_id,
                Transaction.description.contains(order_id),
                Transaction.status == TransactionStatus.COMPLETED
            ).first()
            
            if transaction:
                return {
                    "order_id": order_id,
                    "status": "paid",
                    "amount": transaction.amount,
                    "paid_at": transaction.created_at,
                    "transaction_id": transaction.id
                }
        
        return None


# 支付服务实例
payment_service = PaymentService()